interface
 private
  procedure AppMessage(var Msg: TMsg; var handled: Boolean);
 end;
 implementation

 procedure TForm1.AppMessage(var Msg: TMsg; var handled: Boolean);
 begin
  if (Msg.Message = WM_SYSCOMMAND) and (Msg.wParam = SC_SCREENSAVE) then
  Handled := True;
 end;
 procedure TForm1.FormCreate(Sender: TObject);
 begin
  Application.OnMessage := AppMessage;
 end;
 {
 Note: The Screensaver is only disabled during the lifespan of
 your application.
}